1. Field of the Invention
This invention pertains to a total knee prosthesis.
2. Description of the Prior Art
The articular surface of the knee joint is liable to sustain damage due to trauma, arthritis, and other diseases. In the event that the extent of the damage is such that the function of the knee is irrestorable without surgery, total knee replacement is one of the surgical procedures employed in which the damaged articular surface is resected and a total knee prosthesis is implanted. The Oxford-type total knee prosthesis is one of these prostheses. This prosthesis is an excellent device but there is a limit in flexion capacity and an occasional dislocation of the inserter, particularly at more than 90.degree. of flexion.
New Jersey Meniscal Bearing Knee Replacement is one of the improved modifications of the Oxford-type prosthesis. In this prosthesis, the articulating surface of the femoral prosthesis is made of three different radii in shape, and stems are provided for its fixation. The bottom surface of the inserter has a projecting dovetail which glides in the corresponding groove of the tibial tray. The drawback of this system is that stress associated with knee motion can cause a breakage or cold flow of the projecting dovetail and/or its excessive wear, the particles from which can be harmful to the human body.